And it was certainly not lost on the league when an exhibition match between Manchester United and Real Madrid drew nearly 110,000 fans at the Big House in Michigan last week.
MLS Deputy Commissioner Mark Abbott met this week with a group of reporters to discuss the state of the league, which is in the midst of its 19th season.
"From our experience we had a breakthrough in cultural relevance that we hadn't really seen before," he said.
Given that breakthrough, it wasn't surprising that one of the biggest themes Abbott hit on was expansion.
The league aims to expand from its current 19 teams to 24 teams by 2020. Abbott said further expansion would likely be unwise, based on business models that take into consideration the player pool and television deals.
"When we started the league, we did a lot to study all the other professional sports leagues, and we studied the North American Soccer League, specifically," he said. "We were concerned not about the ultimate size but the rapidness of the expansion. When we think about expansion, we try to think about it strategically."
Orlando will join the league starting next season, along with a second New York team. Atlanta comes on board in 2017 and superstar David Beckham's group will land a Miami team pending a stadium deal.
There are several cities vying for that final spot, including Sacramento, California, home of the popular USL PRO side Sacramento Republic FC. Austin, Texas, and Las Vegas are some of the other cities that the league is looking at.
But MLS will face some challenges in the coming year.
The MLS Collective Bargaining Agreement will expire after this season and player compensation is key to growing the league, which is still snubbed by top homegrown players who choose the big contracts and international notoriety associated with the top global clubs.
But the trend has started to shift with players like Clint Dempsey going to the Seattle Sounders and Michael Bradley playing for Toronto FC.
MLS player compensation totaled $42 million in 2007 and has risen to $115 million this year, according to salaries released by the MLS Players Union and analyzed by The Associated Press. The average grew from $113,800 to $208,100.
Dempsey has $6,695,000 in guaranteed compensation with Seattle and Bradley $6.5 million with Toronto. But the median the figure where an equal number of players are above and below is just under $92,000.
The minimum salaries of $48,500 (for the first 24 players on each roster) and $36,500 (for the final five) figure to be a point of contention in the CBA negotiation.